1. Field of the Invention
The invention relates to an adapter structure having plugs compatible with various electricity standards and having a small size.
2. Description of the Related Art
An adapter typically has a plug and a pair of insertion holes. The plug of the adapter is used to connect to domestic electricity to supply power to conductors inside the adapter. The conductors are mounted corresponding to the insertion holes. When a plug of an electrical appliance is inserted into an electrical socket via the insertion holes of the adapter, the plug comes into contact with the conductors to supply power to the electrical appliance. Such an adapter has only one plug that is not compatible with different electricity standards.
Another type of adapter with various plugs compatible with US, UK and European electricity standards has been commercially available. This conventional adapter allows the user to choose one of the plugs according to the type of electrical socket in place. This type of adapter is convenient because there is no need to buy various adapters for each electricity standard.
Referring to FIG. 1 and FIG. 2, a conventional adapter having various types of plugs includes a casing 90, a first plug 91, a second plug 96, a third plug 100, a pair of conductors 102, and a pair of insertion holes 103. Each first plug 91 includes a pair of rectangular pins 92 and a first portion 93 slidably mounted on the casing 90. A movable fastener 94 moves the first plug 91 forth and back in the casing 90. A rectangular ground pin 95 is pivotally connected to a front side of the casing 90. When the first plug 91 is pushed forward, the rectangular ground pin 95 is driven outward by the first plug 91 to form a third rectangular pin for connection to one domestic electricity standard. The second plug 96 includes a pair of straight pins 97 and a second portion 98 slidably mounted on the casing 90. A movable fastener 98 moves the second plug 92 forth and back in the casing 90. When the straight pins 97 are pushed outward, they can be inserted in another domestic electricity standard. The third plug 100 includes a pair of rod-shaped pins 101 pivotally connected on and unfolded from the front side of the casing 90 for insertion into an electrical socket of yet another electricity standard. The conductors 102 are mounted inside the casing 90 in parallel and respectively electrically connected to the corresponding plugs 91, 92 for inputting various types of electricity standards. The insertion holes 103 are formed through a rear side of the casing 90 to correspond to a pair of outlets of the conductors 102 for receiving a pair of pins of an electric plug of an external electrical appliance to supply electrical power.
However, the plugs 91, 96, 100 of the above conventional adapter exclusively connect to different electric sockets of specific electricity standards. The plugs 91, 96, 100 cannot commonly insert into one electric socket of a certain domestic electricity standard. Therefore, if the adapter has to accommodate all the plugs, the size and production cost of the adapter should be increased with a complex structure.
It is therefore an object of the invention to provide an adapter structure having plugs with different electricity standards, in which the user conveniently chooses one proper plug according to the domestic electricity standard, for example UK or EU electricity standards. The adapter structure of the invention has a simple structure with a reduced size and production cost.
In order to achieve the above and other objectives, the adapter structure of the invention includes a casing, a first plug, a second plug, a pair of conductors and a pair of insertion holes. The first plug has two straight pins pivotally connecting to the casing so that the straight pins are unfolded from the casing or stored up inside the casing. The second plug has two rod-shaped pins with rear ends respectively connected to a base. By pushing a pushing button, the plug moves forth and back inside the casing to unfold or store the rod-shaped pins inside the casing. The conductors are mounted inside the casing in parallel and respectively electrically connected to the first and second plugs, corresponding to outlets of the conductors.
To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention.